No, they're a garbage site because they literally have wrong information. Their homepage has the GTX 1080 as having higher overall performance (over $300) than the Titan X, but lower than the 1070. Now, both the 1070 and 1080 beat the old Titan X in gaming, but the new one beats both of them. It doesn't matter which Titan X they're referring to, because they're wrong either way. In a comparison between the 7970 and the 280x (the same damn GPU, BTW) the 7970 gets an overall higher score, but they recommend the 280x.
http://gpuboss.com/gpus/Radeon-R9-280X-vs-Radeon-HD-7970
Then there's the 460 vs. 750ti. The 460 objectively beats the GTX 750 Ti in practically every single game. Guess what GPUBoss says.
http://gpuboss.com/gpus/Radeon-RX-460-vs-GeForce-GTX-750-Ti
It's not even that they're biased against AMD. They're just incompetent. 1060 vs 960. 1060 is faster in every single way. Guess what GPUboss says.
http://gpuboss.com/gpus/GeForce-GTX-960-vs-GeForce-GTX-1060
They say the 960 is the winner of the comparison, despite the 1060 even getting the higher score.
Here's some more information on why you're wrong:
https://www.reddit.com/r/buildapc/comments/1n10ge/discussion_the_growing_popularity_of_gpucpuboss/
https://www.reddit.com/r/buildapc/comments/26b5fv/discussion_passmark_and_gpucpuboss_are_complete/
https://www.reddit.com/r/pcmasterrace/comments/31mdck/gpuboss_is_not_a_trustworthy_source_of/
https://www.reddit.com/r/buildapc/comments/2h44zw/discussion_quite_a_handful_of_links_to_help_you/
It's totally fine that you didn't know better. It's totally fine that you're completely wrong and don't know it. But now is the time to swallow your pride and admit that you're completely and totally wrong.